//like 系统

// []  "no one like this"
// ["peter"]  "peter like this"
// ["peter", "Alex"]  "peter and Alex like this"
// ["peter", "Alex",Mark]  "peter and Alex  and Mark like this"




const likes = names => {
    switch (names.length) {
        case 0: return 'no one like this'
        case 1: return names[0] + "like this"
        case 2: return names[0] + " add " + names[1] + " like this"
        case 3: return names[0] + ", " + names[1] + " add " + names[1] + " like this"
        default:
            return names[0] + "," + names[1] + ' and ' + (names.length - 2)
                + ' others like this'
    }
}